From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f42.google.com (mail-pj1-f42.google.com [209.85.216.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6838816420 for ; Thu, 11 Jan 2024 09:02:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=fromorbit.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fromorbit.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=fromorbit-com.20230601.gappssmtp.com header.i=@fromorbit-com.20230601.gappssmtp.com header.b="nffDKb6F" Received: by mail-pj1-f42.google.com with SMTP id 98e67ed59e1d1-28ca63fd071so2687794a91.3 for ; Thu, 11 Jan 2024 01:02:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fromorbit-com.20230601.gappssmtp.com; s=20230601; t=1704963739; x=1705568539; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=+g8rx/Js9kR9z/v7+Mn1kTVZXJSN4sbVOGbBgK7rO7Y=; b=nffDKb6F8Wo/dkiC42w6CwY2fB0Y+mLFMG6O3Ar9G4AT+3aJShOCDpaygqiRBvsCT9 bJRk8MojAPNWK6tNvFCzYT2b+Vq3VLxowgudjtaC1sxpQZGaihQLu5nxCJuJm5gHs4y3 mVAY0421ojNpxUjVuiC8+4AannqZtGdZDdjxjQ9/OunWrI3XTgr+8CuqoGA/eIFaDDQe 5fmotibGaDx++fwgVRJhVr1G6MNVVVHYD4jqizj28KEDY1TLbOZ+B/8ozdJRHA1G+IFA iE8Ypqq8WPHCI5P3QEbtoXV52L/VZabHAlVIG1j1EcYbdsuTdhwGk8sQLL4RcTrl2iFf uvNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704963739; x=1705568539; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=+g8rx/Js9kR9z/v7+Mn1kTVZXJSN4sbVOGbBgK7rO7Y=; b=HAJEdOwFwDPX5wSdECCxmaVquCyfS2c6GrdU28LG2clvR6aQ8keZjKusLms28tCQkO 6y8tJo5aR6Lk4yyLXH06hWeccfAn3Z85kqToBMesdXBY+Cg5q5igslBHgiOZqIHzZ1xG XF+ay/ESgKmKWbgZPAiR5X73pE1aSd6wU3Xug7YHkcADORoTv4TnXq4q4T/zSziS5waQ OS6vekyJpORPrU56X9bkESmFaX/YAsT1jfRQhmmbKHzbUQJhL8Ix8LJypkJtk3LM32yZ So0qctdRQ23nh/0+mfVZoCd24KENXCQ0/SapjPCAznNJf4IpBSqDmvcwON7BBQIChWpW 9P7A== X-Gm-Message-State: AOJu0YzpFTr5XRwNfmgM6T7pxwOMc7aBS13MCByHm5gKwORHCnlKzC2f LMKpzBKxynZBJS93UX/FWG+R/GC2aVb7Dn74Xb8yfenqWIQ= X-Google-Smtp-Source: AGHT+IG1anub9IXtnzE0NkJV8/hkigke48pXyoI6NhvhVXOStVvkDJD/vNcvk7XrJv0ekhWe9d6Eug== X-Received: by 2002:a17:90a:df03:b0:28c:8eb9:3029 with SMTP id gp3-20020a17090adf0300b0028c8eb93029mr692801pjb.50.1704963739586; Thu, 11 Jan 2024 01:02:19 -0800 (PST) Received: from dread.disaster.area (pa49-180-249-6.pa.nsw.optusnet.com.au. [49.180.249.6]) by smtp.gmail.com with ESMTPSA id sb8-20020a17090b50c800b0028be1050020sm3144238pjb.29.2024.01.11.01.02.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Jan 2024 01:02:19 -0800 (PST) Received: from dave by dread.disaster.area with local (Exim 4.96) (envelope-from ) id 1rNqx6-008svE-12; Thu, 11 Jan 2024 20:02:16 +1100 Date: Thu, 11 Jan 2024 20:02:16 +1100 From: Dave Chinner To: "Uladzislau Rezki (Sony)" Cc: linux-mm@kvack.org, Andrew Morton , LKML , Baoquan He , Lorenzo Stoakes , Christoph Hellwig , Matthew Wilcox , "Liam R . Howlett" , "Paul E . McKenney" , Joel Fernandes , Oleksiy Avramchenko Subject: Re: [PATCH v3 07/11] mm: vmalloc: Offload free_vmap_area_lock lock Message-ID: References: <20240102184633.748113-1-urezki@gmail.com> <20240102184633.748113-8-urezki@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240102184633.748113-8-urezki@gmail.com> On Tue, Jan 02, 2024 at 07:46:29PM +0100, Uladzislau Rezki (Sony) wrote: > Concurrent access to a global vmap space is a bottle-neck. > We can simulate a high contention by running a vmalloc test > suite. > > To address it, introduce an effective vmap node logic. Each > node behaves as independent entity. When a node is accessed > it serves a request directly(if possible) from its pool. > > This model has a size based pool for requests, i.e. pools are > serialized and populated based on object size and real demand. > A maximum object size that pool can handle is set to 256 pages. > > This technique reduces a pressure on the global vmap lock. > > Signed-off-by: Uladzislau Rezki (Sony) Why not use a llist for this? That gets rid of the need for a new pool_lock altogether... Cheers, Dave. -- Dave Chinner david@fromorbit.com